The present invention relates to a fluid handling system and more particularly, to a cutting fluid handling system that can be used in situations where a fluid stream close to the floor is needed.
Fluid handling systems are commonly used in manufacturing processes to receive cutting fluid, chips, swarf, and other materials from the manufacturing process, filter the fluid, and then deliver that fluid back to the machining equipment. In a typical manufacturing process, there will be numerous machine tools performing various machining, grinding, or part finishing operations. In many of the operations, cutting fluid is used to extend tool life, facilitate the machining operation, and to carry away debris created in the machining process. This fluid and resulting debris is typically delivered to a trough, a conveyor or other fluid transport system which is connected to a pump for pumping the fluid into a filtering system.
Troughs that have been used are traditionally mounted within the floor of the manufacturing facility. In this way, there were few restrictions on the depth and slope of the trough which could be installed. With adequate depth and slope, the fluid and debris can easily travel down the trough to a standard pump where it can then be pumped into the filter. It should be understood, that for optimal operation and flow equilibrium, the surface of the cutting fluid should be parallel to the bottom of the trough as the fluid is flowing through the trough. Further, the depth of the fluid at the end of the trough must be equal or higher to the height of the impeller within the pump in order for the pump to operate. With these considerations, the designer of the fluid handling system selects a desired pump, determines the depth required for the fluid and the proper slope of the trough to obtain the flow and velocity necessary to move the used cutting fluid and debris down the trough to the pump. Due to the ability to mount the trough in the floor of the manufacturing facility, the designer could select any standard pump.
Although the above system works effectively, it limits the versatility of a manufacturing facility and does pose the potential for environmental problems by contaminating the soil in which the trough is installed in the event of a leak in the trough. The fluid handling trough is permanently mounted within the facility floor requiring machinery to be mounted in fairly close proximity to the trough. This restricts the ability of the facility to be rearranged and used for different purposes. Still further, if additional equipment or different equipment is installed, the flow characteristics of the trough may not be sufficient, requiring the trough to be removed and another installed which, due to installation in the floor, is an expensive endeavor.
In view of the limitations of mounting troughs in the floor, it is desirable to mount the fluid handling system above the floor, and below the discharge outlet of the machinery. It should be appreciated by those of ordinary skill in the art, typical machinery is designed so that the work surface is approximately at the height of the waist of the user. As a result, the fluid outlet is typically even lower than waist height. This leaves a very short distance between the floor and the outlet in order to mount the fluid handling trough. As should be appreciated, the trough must have an adequate slope in order to provide the necessary fluid velocity to move the fluid and debris to the end of the trough for entry into a pump for pumping into the filter system. Furthermore, the trough height is limited by the same limitations of height which limits the permissible slope. In order to obtain the appropriate fluid velocity and to handle the appropriate amount of fluid being discharged, the trough must be designed so that it is wide and shallow. In this way, the fluid discharge from numerous machining operations can be handled and handled at the appropriate velocity.
However, this creates a problem with the use of a standard pump because the fluid exiting the trough and entering the pump is very close to the floor and wide. As indicated above, the pump cannot operate unless the impeller is in contact with the fluid being pumped. A standard pump would not function properly if mounted on the floor because the impeller is considerably higher than the fluid level at the end of the trough. This situation would therefore require that a standard pump be mounted in an excavation at the end of the trough thereby creating the same problems of cost, loss of flexibility to easily move the system, and environmental concerns.
The use of conveyors also creates problems with traditional pump systems. Traditional conveyors are usually mounted within either the floor of a factory or within the base of a machine. When mounted within the floor, the conveyor systems have similar flexability issues as the troughs described above. When the conveyors are attached to the base of the machine, other mechanisms are required to separate the contaminants from the fluid. Such mechanisms include additional shredders, crushers, and bins to reduce the contaminants to a size capable of entering the traditional pump. Additional mechanisms such as those described require additional maintenance, cost, and ineffecincies in a fluid handling system. Additionally, traditional conveyors often require auxiliary pumps to speed up the fluid entering the main pump due to the conveyor""s limited velocity capability. Additional pumps also add cost, reliability, and environmental concerns to the overall fluid handling system.
Thus, what is desired is an effecient fluid handling system that is capable of receiving large contaminants in a highly variable rate of fluid at a level close to the floor.
An improved fluid handling system including an improved collection trough and pump assembly. The improved collection trough is mounted above the floor and is specifically constructed with a shape and slope to provide flow of the fluid to an improved pump assembly. The inventive pump receives the dirty cutting fluid from a trough and allows very large objects, even tools which have been inadvertently dropped into the coolant system, to be received and pumped through the centrifugal pump. In general the fluid is delivered to a pump chamber beneath the impeller. The impeller then creates a vortex within the pump chamber to move the fluid and any solids within the fluid out through a discharge outlet.
The inlet mouth of the innovative centrifugal pump has a specific wide and shallow profile and is connected to a vacuum system which can be used to help prime the pump and keep it primed during operation. The vacuum is needed to help prime the pump only if the fluid is not entering the inlet mouth at a sufficient velocity. The suction from the vacuum system also serves to remove the presence of air within the pump that may impede the flow of dirty cutting fluid. The suction also serves to remove air entrained in the fluid, thereby improving the effeciency and liquid handling capability of the pump. The inlet mouth profile of the inventive centrifugal pump facilitates movement of the fluid and the particles, and also lies low to the floor.